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Future Venus Missions
post Oct 16 2020, 08:01 PM
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One also needs to know if "high" and "relatively high" are referring to the same altitudes or if there's some important difference there. I would guess that anything above the clouds, encountering direct solar UV, qualifies equally well as "high" for these purposes, but I never received a paycheck for studying Venus.
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post Oct 17 2020, 03:10 AM
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QUOTE (Xerxes @ Oct 16 2020, 12:34 PM) *
I suppose one would need a great deal more expertise to know whose argument is stronger.

Expertise, maybe. But as humans, we can also employ our heuristic tools of caricature, profiling and prejudice.

Therese Encrenaz has been in *planetary* spectroscopy a long time. I think (and my Planetary Climate book gives many examples) in planetary science there are many instances of spectroscopic detections being disproved by in-situ or other data, which make some people (like her) cautious. In stellar astronomy (which seems to be where the Cardiff group has more pedigree), I could imagine there are fewer disproved 'discoveries' just because there are fewer ways to confirm or refute initial announcements.

So, IMHO, if Therese says it isnt in her data, then it isnt in her data... (and knowing her, she wouldnt say it wasnt there on Venus, only that there wasnt evidence for it in her data).

It may be non-PC to consider such meta-factors, but at the hairy edge of detectability, one is obliged - Bayeswise - to weigh all the information.

There are sadly a lot of incentives in the journals and the media to talking up anything that could bear on life in the universe - indeed Nature Astronomy even had an editorial congratulating itself on how much press the paper had generated and how this was only possible because of their media embargo policy. Cui bono....

All this said, Venus deserved the attention.

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post Oct 27 2020, 11:35 PM
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For what it's worth, this is new on the arxiv, not yet refereed:
Re-analysis of the 267-GHz ALMA observations of Venus: No statistically significant detection of phosphine
I.A.G. Snellen, L. Guzman-Ramirez, M.R. Hogerheijde, A.P.S. Hygate, F.F.S. van der Tak

"...The reported 15σ detection of PH3 1−0 is caused by a high-order polynomial fit that suppress the noise features in the surrounding spectrum. ...Low-order spectral baseline fitting shows a feature near the expected wavelength at a signal to-noise of only ∼ 2."

It does come with a front page caveat that there has since been an update to the ALMA processing pipeline [while this re-analysis was in work], that they haven't fully analyzed. It notes that though many of the "spurious ripples" are gone, they still see no clear PH3 feature.
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